Lycopene Improves Maturation Rate and Antioxidant Status of in vitro Matured Mouse Oocytes

Abstract

The present study aimed to investigate the effect of lycopene supplementation to the in vitro maturation (IVM) medium of mouse oocytes on their maturation rate and oxidative biomarkers levels. Lycopene concentrations of 50, 100, 200, and 400nM were tested. The effects of lycopene on maturation rate of mouse oocytes under in vitro oxidative and heat stress conditions were also explored. Cumulus-oocyte complexes (COCs) were collected from ovaries of super-ovulated mice via puncturing technique and incubated in the IVM medium for 17h. To simulate oxidative stress, COCs were incubated in an IVM medium containing 100µM hydrogen peroxide (H2O2) with or without lycopene. Additionally, to mimic heat stress, COCs were in vitro matured at 40℃ with or without lycopene. Among the four tested lycopene concentrations, the 200nM lycopene achieved the highest improvement in oocyte maturation. The oocyte concentrations of H2O2, malondialdehyde (MDA), total antioxidant capacity (TAC), reduced glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD) were altered by lycopene treatment: H2O2 and MDA were significantly decreased, meanwhile TAC, GSH, CAT and SOD were increased. IVM rates of mouse oocytes revealed a significant decline following their exposure to heat and oxidative stresses. Interestingly, lycopene supplementation rescued the IVM rate of the oxidative stressed or the thermally challenged mouse oocytes as they appeared comparable to those of the control oocytes. Taken together, our data report beneficial effects of lycopene on mouse oocytes and suggest lycopene as a candidate factor for improving the quality of mammalian oocytes and embryos.